Mariner's Hand App — tools for life at sea

On Google Play · iPhone coming soon

Three apps for ship’s officers

Compass checks, draft surveys and the deck department’s paperwork — each one made for the job it is named after, and every one works with no signal.

Compass Observation App

Celestial navigation & compass toolkit

Check your gyro and compass, reduce your sights and fix your position, and find any star or planet in the sky — all computed on your phone, fully offline.

Gyro and compass error by azimuth or amplitude, with SOLAS cautions
Sight reduction and a plotted running fix from two or more sights
Swing ship to a smoothed deviation card and a clean PDF report
AR sky and star dome with every star, planet and constellation

Google Play Learn more App Store soon

Mariner’s Draft Survey

Draft survey & cargo planning

From the six drafts to the final cargo figure, with the working behind every number — and the cargo work around it, for bulk carriers.

Mean of means, trim and list corrections, deductibles and the cargo by difference
Stowage plans, loading sequences and a draft log against the plan
Draft Reader for photos of the marks; Heel Meter for the side you cannot read
Ballast Watch with alarms while pumping, even with the app closed

Google Play Learn more App Store soon

DeckWatch

Work planner for deck officers

The complete work planner for the deck department — offline-first, with optional cloud sync and crew sharing.

Planned maintenance and certificates, with reminders before anything lapses
Port State Control and the full RightShip (RISQ) checklist, with guidance
Rest hours checked against STCW and MLC limits as you log them
Ballast Water and Garbage Record Books, Statement of Facts, watch handover

Google Play Learn more App Store soon

Offline firstEverything is computed on the device. No signal needed, but for the DSC station reports.
No ads, no trackingNo accounts to make, no subscriptions, nothing sold on.
Nothing to installThe tools run in your browser, the apps on your phone. No sign-up.
Shows its workingEvery figure can be traced back to the numbers behind it.

Free browser tools

Eight tools, nothing to install

They run in your browser with no account, and what you type stays on the computer it is typed on. Only DSC Test Stations goes online, to read ships’ reports.

DSC Test StationsWhich coast station to call for the weekly DSC test, and on which band — nearest first, coloured by what ships have reported. Document FillerOne workbook of ship’s data fills every form a port call asks for — PDF, Word, Excel, HTML — and writes AMVER, NOR and Letters of Protest. Dewpoint, Ventilation & PaintVentilate or not by both rules, coal gas trends, enclosed space records and paint conditions — with the log kept in Excel. Unit ConverterThe units a deck officer reaches for — the three tons spelled out, stowage factor and density crossed properly, cargo intake worked on the page. True & Relative WindWhat the anemometer reads and what the wind is doing, over the ground and through the water, with the drift angle and Beaufort force. InterpolatorRead between the rows of any ship’s table, corrections chained in order, with every step shown and extrapolation flagged. Dynamic UKCUnder-keel clearance per waypoint against one policy — squat, roll, pitch, tide and CATZOC — with pass or fail on every leg. Risk AssessmentA structured way to think a job through before it starts, at two levels. It prompts, never answers, and nothing is ever ticked for you.

Browse all the tools

For the people who keep ships running

Every app and tool here started as a real problem on a real voyage. Got a problem of your own that deserves a tool? Tell me about it.